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Publication of BE373481ApublicationCriticalpatent/BE373481A/fr
H01K9/00—Lamps having two or more incandescent bodies separately heated
H01K9/02—Lamps having two or more incandescent bodies separately heated to provide substitution in the event of failure of one of the bodies
H01K9/06—Lamps having two or more incandescent bodies separately heated to provide substitution in the event of failure of one of the bodies with built-in device, e.g. switch, for automatically completing circuit of reserve body